Spacious: The rooms are hidden deep underground (Picture: South West Water /PA)

Several blast-proof doors will deter burglars and a decontamination room will help keep it spick and span.

Chris Shapland, the Authority’s property manager, explained: ‘We regularly auction redundant assets to reduce our costs and keep customers’ bills as low as possible, but this is the first time we’ve offered a genuine piece of Cold War history.

Where’s the shower? (Picture: South West Water /PA)

‘Novelty sites with small areas of surplus land always attract strong interest as people are able to invest relatively modest sums for their “little bit of England”.

‘Several of our former storage reservoirs and pumping stations have been converted by their new owners into unusual homes. It will be interesting to see what happens to the bunker – you never know who could end up using it.’

Some added extras (Picture: South West Water /PA)

The bunker and some attached land will be auctioned on March 25 by Webbers Estate Agents.